Abstract:
Water samples were collected from 11 public-supply wells and 11 domestic wells during the fall of 2004 for analysis to characterize the chemical quality of ground water in the Lake Champlain basin in New York State. Samples were analyzed for 216 physical properties and constituents, including inorganic compounds, nutrients, metals, radionuclides, pesticides and pesticide degradates, volatile ... organic compounds, and bacteria. Sixty-nine percent (148) of the constituents were not detected in any sample: the other 31 percent (68 constituents) were detected at concentrations above laboratory reporting levels.

The color of samples from three wells equaled or exceeded the USEPA secondary standard of 14 platinum-cobalt units. The pH of samples from two wells exceeded the range of the USEPA secondary drinking-water standards (6.5 to 8.5) Alkalinity and water hardness in the Adirondack Mountain part of the basin was lower than in the Champlain Valley lowlands. The cation with the highest concentrations was bicarbonate. No cation or anion concentrations exceeded MCLs. The predominant nutrient was nitrate, but no samples exceeded the 10 mg/L MCL. The metals with the highest concentrations were iron and strontium. Concentrations of several metals exceeded secondary drinking-water standards, including iron (300 ug/L or greater in samples from 9 of the 22 wells), manganese (50 ug/L or greater at 3 wells), aluminum (50 to 200 ug/L and greater at 2 wells), and zinc (5,000 ug/L or greater at 1 well). Concentrations of radon-222 ranged from 40 to 6,930 pCi/L; samples from eight wells had concentrations that exceeded the proposed MCL for radon (300 pCi/L). thirteen pesticides and their degradates were detected in the samples; most were degradates of broadleaf herbicides such as metolachlor, alachlor, and atrazine. Three VOCs were detected - toluene, methyl tert-butyl ether (MTBE), and ethyl tgert-butyl ether (ETBE); all of which are used as gasoline additives. None of the pesticides or VOCs detected exceeded established MCLs. Samples from four wells tested positive for total coliform; two of these also tested positive for E. coli. any positive sample is considered to be above the MCL for total coliform and E. coli. The samples with the highest bacterial concentrations in a heterotropic plate count test were from domestic wells; but no smaple exceeded the MCL of 500 colonies per mL.